For applications in the vehicle radar field, there is a continuous increase in integration. Particularly by the use of Si/SiGe technologies (silicon/silicon-germanium), a significantly higher degree of integration may be achieved as compared to GaAs (gallium-arsenide). The reproducibility of passive distributing networks is also considerably higher on-chip, i.e. integrated on the chip, than on radio frequency circuit board material, such as Rogers 3003™. This, in turn, may require ways to be able to manage this high integration in highest frequency ranges. For example, the on-chip isolation between different circuit components is very problematic at these high frequencies.
Currently, what is used for realizing vehicle radar circuits in so-called MMICs (monolithic microwave integrated circuits) are integrated single mixers fed on the local oscillator side and on the antenna side correspondingly by distributing networks implemented on the radio frequency circuit board material. Reproducibility is limited due to manufacturing tolerances on the substrate, and space requirements may be relatively high. In addition, unbalanced and/or unsymmetrical or “single-ended” RF transitions in the form of, for example, bond interfaces are used. Due to these unbalanced transitions where the compensation current flows to the signal current in the on-chip reference plane, an RF signal is mapped on the on-chip reference plane that may disturb the circuits and may thus limit the isolation of adjacent blocks on the chip.